Gate Metal Dependent Reverse Leakage Mechanisms in AlGaN/GaN Schottky Diode

The dependence of the gate leakage mechanism in the AlGaN/GaN Schottky diode on the metal-semiconductor (MS) interface state has been investigated. Schottky gates with Au, Pt, Pd, and Ni showed the remarkably different gate leakage mechanisms in the reverse direction. Through the analysis of the temperature dependent reverse leakage currents, it is shown that the discrete energy levels of MS interface states are the key factor in determining whether the leakage mechanism at the high temperature over 300 K is caused by the electron tunneling or by the Frenkel-Poole emission from the MS interface state to the conductive dislocation state. (C) 2013 The Japan Society of Applied Physics